The present invention is generally concerned with home garden tools, and more specifically, relates to powered hand-held devices particularly adapted for soil cultivation.
Such ground working tools, known by a variety of descriptive names, including cultivator, weeder, hoeing machine, and the like, have been the subject of patents for a substantial number of years as will be recognized from the following patents, a number of which are specifically directed to powered hand-held devices: U.S. Pat. Nos. 369,600, Hicks, September 1887; 1,592,825, Gardner et al, July 1926; 2,625,867, Hands, Jr., January 1953; 3,616,862, Van Der Lely, November 1971; 4,003,436, Foster et al., January 1977; 4,133,389, Ruhl et al, January 1979; 1,800,229, Germany, May 1970; 530,635, Italy, July 1955; 379,225, U.S.S.R., June 1973; 386,596, U.S.S.R., August 1973.
The patent to Ruhl et al presents a hand-held power driven cultivator wherein a pair of angled tillers are mounted below the housing on a pair of exposed shafts. The individual blades or tines of the tillers may pass alternately across the center line of the cultivator as the tillers move in a counter-rotational direction tending to pull the cultivator forwardly. No provision is made for preventing the winding of weeds, roots, or other debris about the exposed tiller shafts, nor does there appear to be any particular concern with any problems which might arise with regard to a clogging of the tillers, particularly in those instances wherein they may pass across the center line of the cultivator. The two Russian patents, as well as the patent to Gardner et al, also disclose inclined tillers and tiller shafts, while the remainder of the patents present devices with vertical shafts. In each instance, there appears to be little or no provision for preventing debris accumulation around the shaft. The only suggestion of this problem is in the patent to Foster et al wherein specific provision is made to oscillate the tilling members through a relatively small angle to prevent the wrapping of roots and growth around the tines. It is doubtful whether this oscillating movement will provide the superior cultivating action achieved by rotating tillers, and in particular tillers presented in pairs and driven in counter-rotational directions.